Internal hernia due to mesenteric defect.

Internal hernia is one of the rare causes of small bowel obstruction. A congenital mesenteric defect is very rare, but can potentially cause internal hernia with consequent incarceration or strangulation of the small intestine. An 18-year-old woman was brought to our emergency department with sudden onset lower abdominal pain. She had no remarkable past medical history and took no medications. An emergency laparotomy was performed. On exploring the abdominal cavity, the mesenteric defect was detected in the jejunal region, 3 cm in size. Loops of small intestine had gone through the defect three times in a complex manner and strangulated. Gangrenous intestine was resected and a primary anastomosis was performed. An adult congenital mesenteric defect is rare; however, it should be considered as one of the differential diagnoses in a relatively young patient with bowel obstruction without external hernia, previous abdominal surgery or trauma.